Microstructured surfaces have been widely used for many applications such as diffusers, solar cell panels, prismatic retroreflective films, microfluidics, and control surfaces for flow and heat/mass transfer. In a wide range of optical applications surfaces are textured to redirect, redistribute, or diffuse light to enhance brightness, diffusion, or reflection. Micro channels are machined on heat sinks for power electronics to improve the cooling efficiency. Microfluidic devices embedded with micro channels have been used for clinical diagnostics, chemical synthesis, biomedical analysis, etc. These micro-scale features are produced on surfaces with high precision and accuracy, and usually transferred to the surfaces of final products with a submaster fabricated from a master containing the desired microstructure. The master may be produced using various micro-machining techniques, such as precision milling or turning, on a workpiece typically made of machinable metals like copper or nickel. The submaster may be formed on the master, for example, by a micro-replication process such as electroforming.
Defects in a master, and a submaster formed from the master, due to the separation of the submaster, may occur. For example, when a submaster is formed on a master by a micro-replication process such as electroforming, and the submaster is then separated from the master for further processing, defects may occur to the master and submaster during separation. For example, during the separation, rubbing and reattachment between the master and submaster tend to damage the delicate microstructure not only on the submaster but also on the master, causing defects including scratches, dents, and loss of geometry definition of the structures.